Thromboxane A.sub.2 is an arachidonic acid metabolite produced by blood platelets, which causes considerable constriction of blood vessels and induces platelet aggregation. Thromboxane A.sub.2 production is increased in disorders such as angina pectoris or cerebrovascular accident, and it plays a very important part in all processes leading to thrombotic disorders.
It was hence especially advantageous to synthesize substances capable of inhibiting the aggregation-promoting and vasoconstrictor activities of thromboxane A.sub.2, either as thromboxane A.sub.2 receptor antagonists, or as thromboxane A.sub.2 synthase inhibitors.
Alkenecarboxylic acid compounds possessing antithrombotic properties have been described in the literature. This applies, in particular, to the compounds described in Patent EP 405,391. The compounds described in the present invention, apart from the fact that they are new, possess pharmacological properties that are markedly more intense than those of the other compounds described in the prior art.
They are hence useful as thromboxane A.sub.2 antagonists and as thromboxane A.sub.2 synthase inhibitors in the treatment or prevention of thrombotic disorders such as vascular accident. These thrombaxe A.sub.2 antagonists also possess properties of protecting the stomach wall (M. L. OGLETREE et al, J. Pharm. and Exp. Therap., 263 (1), 374-380).